Well I've learnt somthing new today, DT. Thanks for that. Not sure when it'll pop up in conversation with my elderly French rellies, but you never know.
there are two excellent toilet-room books for learning French slang, inc all the naughty idioms, both titled "Merde" and I am sure you know what that means - I use it a fair amount instead of "Shyte"
More seriously, it also has a lot of the day to day slang. For example, how often do we use the word children, substituting the sproglets, kids, etc. Same in French - les enfants becomes les gamins or les gosses, old folk, "les vieux" etc etc.